The Arizona-Sonora Desert Museum has a digital library containing thousands of photographs of plants and animals. The digital library is an interactive site that has a kidâs page with videos, animal sounds, and games.
The photo is courtesy of: http://members.multimania.nl/onager/ballista.htmlMangonelThe Mangonel is what many people think of when they think of a catapult. From the Latin word manganon meaning engine of war. The Mangonel was invented by the Romans in 400 BC. The Mangonel consists of a long wood arm with a bucket (early models used a sling) with a rope attached to the end. The arm is then pulled back (from natural 90o angle) then energy was stored in the tension of the rope and the arm. Then the bucket would be loaded.
A trebuchet is a catapult, a common type of siege engine which uses a swinging arm to throw a projectile. The traction trebuchet first appeared in Ancient China during the 4th century BC as a siege weapon. It spread westward, probably by the Avars, and was adopted by the Byzantines in the mid 6th century AD. It uses manpower to swing the arm. The later counterweight trebuchet, also known as the counterpoise trebuchet, uses a counterweight to swing the arm. It appeared in both Christian and Musli